Flaw detector mechanism



July 19, 1938. DE LANTY 2,124,411

. FLAW DETECTOR MECHANISM Filed Nov. 17, 1933 Zinventor LOPEN .1 DE AAA/TY,

Patented July 19, 1938 UNITED STATES FLAW DETECTOR-MECHANISM Loren J. De Lanty, Spring Valley, N. Y., assignor to Sperry Products, Inc., Brooklyn, N. Y., a corporation of New York Application November 1'7, 1933, Serial No. 698,522

10 Claims. (Cl. 172-311) This invention relates to flaw detector mechanism for electrical conductors, and, more particularly, to.Sperry rail fiaw detector cars. These cars employ a mechanism consisting of a generator for supplying current to the rail to establish an electromagnetic field surrounding the same and then causing induction means to explore the said field in constant relation to the rail so that any variations in fiux inthe field caused by the presence of flaws will result in inducing an E. M. F. which, after being suitably amplified, may be caused to operate an indicator,

such as a recorder. At the same time that the recorder is actuated, there is operated another inlli dicator, in the form of a paint gun for spraying paint on the rail at the-point where a fissure is detected.

It has beenfoundthat at times the pens operating on the recording ch'art were operated to 20 difierent degrees, depending upon the duration of v the impulse transmitted by the amplifier. The pens, which normally trace a straight line onthe moving chart, are actuated by the output of the amplifier tocause a jog in the line, and these 25- jogs were found at times to be very small and at other times to be of substantial length. It is the principal objectof my invention to provide means which will insure a constant degree of operation of the pens when there is an impulse 30 from the amplifier, regardless of the duration-of said impulse.

At the same time that the output of the amplifier operates the recording mechanism described above, it also operates the paint gun through as means such as a relay. This operation also was found to be variable so that at times a long paint mark was obtained and at times only a small paint mark was obtained. It is, therefore, a

further object of my invention to provide means 40 which willinsure a constant degree of operation of the paint gun regardless of the size of the output from the amplifier.

Further objects [and advantages will become apparent from the following detailed description ll thereof. w

In the accompanying drawing,

Fig. 1 is a side elevation of a portion of a Sperry rail flaw detector car to which my invention is adapted to be applied.

50 Fig. 2 is a view largely diagrammatic, illustrating the principle underlying my invention.

The flaw detector mechanism, which I have shown employed in the Sperry rail fiaw detector car, is mounted on a rail car adapted totravel along the rails and comprises a car body In, a

portion of which is shown, within which is mounted a generator G for supplying current to a portion of the rail through means such as sets" of spaced brushes II and I2 for establishing an electromagnetic field surrounding the rail R. 5 Said brushes may be mounted on a current brush carriage l5 which is normally held in elevated position by means such as retractile springs (not shown) and cables l8. When it is desired to lower the arriage to efiective position in engage- 10 ment with the rail, this may be done either by a suitable leverage connection or by means of a compressed fluid supplied to cylinders I9 to lower piston rods 20 which'are connected to the carriage. Said carriage may ride upon the rail on flanged wheels 2|. 1

There'is provided means for detecting any variations in the electromagnetic field caused by the presence of flaws in the rail. Said means comprises a pair of induction coils 23 mounted within the housing 24 supported on a detector carriage 25 which may be mounted on the current brush carriage I5 for movement independent thereof by means such as loose-' fitting bolts 26 and springs 21. Said detector carriage may be caused to en- 25 gage the rail by any suitable means, such as rollers 28. I As the car moves along the rails the induction coils 23 will normally cut a constant number oi lines of force. Any variations in the current sup- 30 ply will have no eflect upon the coils 23 because said coils are of equal inductance and oppositely connected so that such variation in the electro magnetic field caused by variations in current supply will affect said coils equally, oppositely, and simultaneously. The same'is true when the housing 24 moves with respect to the rail R to change the spacing between the two. When,. however, a region of fiaw is encountered, first one and then the other of said coils will cut a difier- 40' cut number of lines of force which will induce a differential E. M. R, which, after being suitably amplified by the amplifier A, may be caused to operate an indicating mechanism vsuch as pen magnet 29 operating pen P on a chart C. The

output ofthe amplifier A may also operate a paint gun 40 as by means of a paint gun magnet 30 controlling a valve 3|.

In order to insure a constant degree of actuation of pen P as well as the paint gun 40; I may cause the amplifier A to act upon an independent circuit in which there is positioned a condenser of large capacity designed to be normally charged, but which the amplifier causes to discharge through the pen and paint gun relays when an impulse of a duration in excess of a predetermined minimum is passed through the amplifier. For this purpose I have provided a condenser 32 of large capacity in circuit with battery B. This circuit extends through an armature 33 and a contact 34 and said circuit is normally closed by means such as spring 35. The battery B normally charges the condenser 32. When an impulse is sent through amplifier A due to the differential E. M. F. being induced by coils 23, the output of amplifier A is caused to actuate the armature 33 of a relay 34 against the action of restraining spring 35 to cause the armature 33 to make contact at 36, thus breaking the charging circuit from battery B to condenser 32 and connecting said condenser to the magnets 29 and 30. There is thus formed a discharge circuit so that the condenser may discharge the accumulated charge thereon in every case where the duration of the impulse from the amplifier is in excess of a predetermined minimum. Since the capacitance and dielectric resistance of the condenser are constant it will take a definite charge each time that the circuit is closed through the condenser 32 and battery B and thus a definite and constant total output of energy is obtained every time the condenser discharges. The characteristic of the condenser is also such as to permit quick charging so that no appreciable time interval is necessary to place a full charge upon the condenser 32. Suitable small condensers 31 and 38 and resistors 4|,

- 42 may be connected in parallel with the contacts 34, 33 and 33, 36, respectively, to prevent sparking at the discharge.

If desired, instead of connecting the two magnets 29 and 30 in series, they may be independent, and a separate condenser circuit similar to that shown may be provided for each magnet. Also, instead of one relay 34 being provided for actuating the armature 33, separate relays with separate armatures may be provided for the separate condenser circuits to the pen magnet 29 and the paint gun magnet 30, respectively.

In accordance with the provisions of the patent statutes, I have herein described the principle and operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrativeand that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combinaion and relations described, some of these may be altered and oth ers omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a flaw detector for electrical conductors which normally comprises flaw responsive means,

dered efiective, and means whereby said responsive means renders said mechanism effective once in response to each flaw.

- 2. In a flaw detector for electrical conductors which normally comprises flaw responsive means,

dicating means places uniform marks of predetermined size upon said conductor in the region of flaws, said last-named means comprising an electrical operating mechanism for said indicating means comprising means for storing a constant quantity of electrical energy when ineffective to operate said indicating means, means for discharging the same in a single output when rendered elfective, and means whereby said responsive means renders said mechanism efiective once in response to each flaw.

3. In a flaw detector for electrical conductors which normally comprises flaw responsive means, indicating means, and means whereby said indicating means places uniform marks of prede-' termined size upon said conductor in the region of flaws, said last-named means comprising an electrical operating mechanism for said indicating means comprising means including a condenser and a'source of electrical energy for storing a constant quantity of energy when ineffective to operate said indicating means, means for discharging the same in a single output when rendered effective, and means whereby said responsive means renders said mechanism effective once in response to each flaw.

4. In a flaw detector for electrical conductors which normally comprises flaw responsive means, marking means, said flaw responsive means being adapted to generate impulses of varying duration in response to flaw and means whereby said impulses actuate said marking means, means for obtaining uniform marks of predetermined size upon said conductor adjacent the flaws, said last-named means comprising means for limiting said actuation to a single output of constant degree irrespective of the duration of said impulses in excess of a predetermined minimum duration.

5. In a flaw detector for electrical conductors which normally comprises flaw responsive means, indicating means, and means whereby said indicating means places uniform marks of predetermined size upon said conductor in the region of flaws, said last-named-means comprising an operating mechanism 'for said indicating means, said mechanism including a condenser, a source of energy, means whereby said source normally charges said condenser, means for discharging said condenser in a single output, means whereby said indicator is actuated when said condenser discharges, and means whereby said responsive means discharges said discharge means once in response to each flaw.

6. In a flaw detector for electrical conductors which normally comprises flaw responsive means, indicating means, and means whereby said indicating means places uniform marks of predetermined size upon said conductor in the region of flaws, said last-named means comprising an operating mechanism for said indicating means, said mechanism comprising an electric circuit, said circuit including a condenser, means for charging the condenser, and means for discharging the condenser in a single output, and means whereby said responsive means discharges said discharge means once in response to'each'flaw.

7. In a flaw detector for electrical iconductors which normally comprises flaw responsive means, indicating means, and means whereby said indicating means places uniform marks of predetermined size upon said conductor in th''re'gion of flaws, said last-named means comprising an operating mechanism for said indicating means,

said mechanism comprising an electric circuit,

said circuit including 'a condenser, means for charging the condenser, means for discharging the condenser in a single output, means whereby each of said charging means and discharging means is rendered eifective and ineffective when the other is rendered ineiiective and effective, respectively, and means whereby said responsive means discharges said discharge means once in response to each flaw.

- 8. In a flaw detector for electrical conductors which normally comprises flaw responsive means, indicating means, and means whereby said indieating means places uniformmarks of predetermined size upon said conductor in the region of flaws, said last-named means comprising an operating mechanism for said indicating means, said mechanism comprising an electric circuit, said circuit including a condenser, means normally efiective for charging the condenser,.means for discharging the condenser in a single output,

' means whereby each of said charging means and 3 adjacent the flaw and means whereby said flaw responsive means actuates said marking means,

means for limiting to, a constant predetermined.

size the mark placed upon the rail, said lastnamed means including an electric circuit having a condenser of predetermined capacity, means whereby said circuit controls the energizatlon of said marking means, and means whereby the impulse from said responsive means controls said circuit to render'the' same efiective to operate said marking means once in response to each flaw.

- 10. In a rail flaw detector mechanism which normally comprises means whereby said flaw responsive means generates impulses of variable duration in response to flaw, marking means for placing a mark on the rail adjacent the flaw and means whereby said flaw responsive means actuates said marking means, means for limiting to a constant predetermined size the mark placed'upon the rail, said last-named means including an electric circuit having a condenser of predetermined capacity, means for normally charging said condenser, means normally ineffective whereby the output of said condenser controls the energization of said marking means,

and means whereby the impulse from said responsive means renders said charging means ineffective and renders said condenser efiective to energize said'marking means to operate the same once in response to each flaw.

LORENJ. DE LANTY. 

